Related papers: New Experimental Constraints for the Standard Mode…
Motivated by the LHCb measurement of the hyperon decay mode $\Sigma^+\to p\mu^+\mu^-$ and prospects for improvement, we revisit the estimates for the rate and muon forward-backward asymmetry within the standard model and beyond. The…
Two recent low energy precision experiments are considered, in order to illustrate how limits set by these measurements for couplings beyond the Standard Model are complementary to high energy constraints.
We compute the dominant, logarithmically enhanced radiative corrections to the electron spectrum in the bound muon decay in the whole experimentally interesting range. The corrected spectrum fits well the TWIST results. The remaining…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…
Working within the Standard Model effective field theory approach, we examine the possibility to test charged lepton flavour violating (cLFV) new physics (NP) by angular measurements of the outgoing electron and positrons in the polarised…
We studied the radiative muon decay $\mu^+ \to e^+\nu\bar{\nu}\gamma$ by using for the first time an almost fully polarized muon source. We identified a large sample (~13000) of these decays in a total sample of 1.8x10^14 positive muon…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results obtained at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…
We have performed a global analysis of muon decay measurements to establish model-independent limits on the space-time structure of the muon decay matrix element. We find limits on the scalar, vector and tensor coupling of right- and…
A search for physics beyond the standard model (SM) in final states with an electron or muon and missing transverse momentum is presented. The analysis uses data from proton-proton collisions at a centre-of-mass energy of 13 TeV, collected…
Latest Lattice results on $D$ form factors evaluation from first principles show that the standard model (SM) branching ratios prediction for the leptonic $D_s \to \ell \nu_\ell$ decays and the semileptonic SM branching ratios of the $D^0$…
Polarized $\Lambda_b \to \Lambda \gamma$ decays at the Z pole are shown to be well suited for probing a large variety of New Physics effects. A new observable is proposed, the angular asymmetry between the $\Lambda_b$ spin and photon…
We explain the 2.3 sigma deviation in the recent measurements of the neutral B mesons decay into muon pairs from the standard model prediction in the framework of supersymmetric grand unified models using anti-symmetric coupling as a new…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…
A search is performed for heavy neutrinos in the decay of a $W$ boson into two muons and a jet. The data set corresponds to an integrated luminosity of approximately $3.0 \text{ fb}^{-1}$ of proton-proton collision data at centre-of-mass…
We review constraints on the minimal supersymmetric extension of the Standard Model (MSSM) coming from direct searches at accelerators such as LEP, indirect measurements such as b -> s gamma decay and the anomalous magnetic moment of the…
To measure the muon decay parameters with high accuracy, we require an array of precision drift detector layers whose relative position is known with very high accuracy. This article describes the design, construction and performance of…
We compute the spin asymmetry of the muon decay through O(alpha^2) in perturbative QED. These two-loop corrections are about a factor five (twenty) smaller than the current statistical (systematic) uncertainty of the most precise…
The new CDF II measurement of $W$-boson mass shows a 7$\sigma$ deviation from the Standard Model (SM) prediction, while the recent FNAL measurement of the muon $g-2$ shows a 4.2$\sigma$ deviation (combined with the BNL result) from the SM.…
We have studied the muon decay energy spectrum from a sample of stopping muon events acquired during the test run of the ICARUS T600 prototype. This detector allows the spatial reconstruction of the events with fine granularity, hence the…